Cod liver oil shown to be effective in slowing down joint destruction in osteoarthritis, say scientists
Arthritis Research Campaign-funded scientists have revealed new clinical data showing that cod liver oil can slow the destruction of joint cartilage in patients with osteoarthritis.
The clinical study was led by Professor Bruce Caterson and Professor John Harwood of Cardiff University , and Professor Colin Dent, orthopaedic surgeon at University of Wales College of Medicine, working on an arc special purposes grant.
Preliminary data from a small clinical study of 25 patients awaiting joint replacement surgery showed that 86 per cent of patients with arthritis who took cod liver oil capsules daily, had absent or significantly reduced levels of one of the enzymes that cause cartilage damage compared to 26 per cent of those given a placebo oil capsule. In addition, the result showed a marked reduction in some of the enzymes that cause joint pain, in those patients taking the cod liver oil.
Research published by the Cardiff team last year showed that cod liver oil appeared to be effective in reducing cartilage destruction in laboratory experiments, but this is the first time its efficacy has been demonstrated on patients.
Speaking at a press conference held at the Royal College of Surgeons in London, Professor Caterson said: "This breakthrough is hugely significant because it demonstrates the efficacy of a dietary intake of cod liver oil in patients with osteoarthritis taken prior to their joint replacement surgery. The data suggests that cod liver oil has a dual mode of action, potentially slowing down the cartilage degeneration inherent in osteoarthritis and also reducing factors that cause pain and inflammation.
"What these findings suggest is that by taking cod liver oil, people are more likely to delay the onset of osteoarthritis and less likely to require multiple joint replacements later in life."
In the study, 25 patients on an NHS waiting list were recruited 10-12 weeks prior to total knee joint replacement surgery. Half of the patients were given two daily capsules containing 1000mg cod liver oil and half given placebo capsules. At the time of surgery, samples of cartilage and joint tissue were taken from the knee joint and subjected to analysis.
The clinical study did not measure whether cod liver oil reduced painful symptoms in patients, but concentrated on the action of enzymes and inflammatory mediators that cause cartilage damage and inflammation. Those patients taking cod liver oil had greatly reduced levels of aggrecanase and collagenase (enzymes that destroy cartilage) and in some of the substances that cause inflammation. However, COX-2 (an important inflammatory mediator) did not show any reduction.
Full data from the study is currently being prepared for publication in a peer -reviewed medical journal.
Professor Caterson added: "Our results suggest that people who have suffered sporting injuries, that predispose them to the early onset of osteoarthritis (e.g. meniscal tears or cruciate ligament rupture) should consider taking cod liver oil to slow the progression of their disease."
Professor Colin Dent said: "This is where science and old wives' tales coincide. Our findings are consistent with advice that taking cod liver oil in early adulthood could delay the onset of osteoarthritis and reduce the harmful symptoms associated with the disease."
